We add the ostd setting for mt8195. It introduces a KE for the
previous SoC which doesn't have ostd setting. This is the log:
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000080
...
pc : mtk_smi_larb_config_port_gen2_general+0x64/0x130
lr : mtk_smi_larb_resume+0x54/0x98
...
Call trace:
mtk_smi_larb_config_port_gen2_general+0x64/0x130
pm_generic_runtime_resume+0x2c/0x48
__genpd_runtime_resume+0x30/0xa8
genpd_runtime_resume+0x94/0x2c8
__rpm_callback+0x44/0x150
rpm_callback+0x6c/0x78
rpm_resume+0x310/0x558
__pm_runtime_resume+0x3c/0x88
In the code: larbostd = larb->larb_gen->ostd[larb->larbid],
if "larb->larb_gen->ostd" is null, the "larbostd" is the offset(e.g.
0x80 above), it's also a valid value, then accessing "larbostd[i]" in the
"for" loop will cause the KE above. To avoid this issue, initialize
"larbostd" to NULL when the SoC doesn't have ostd setting.
Signed-off-by: Yong Wu <[email protected]>
---
change note: Reword the commit message to show why it KE. and update the
solution via initializing "larbostd" is NULL explicitly in the non-ostd
case.
---
drivers/memory/mtk-smi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index b883dcc0bbfa..e201e5976f34 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -241,7 +241,7 @@ static void mtk_smi_larb_config_port_gen2_general(struct device *dev)
{
struct mtk_smi_larb *larb = dev_get_drvdata(dev);
u32 reg, flags_general = larb->larb_gen->flags_general;
- const u8 *larbostd = larb->larb_gen->ostd[larb->larbid];
+ const u8 *larbostd = larb->larb_gen->ostd ? larb->larb_gen->ostd[larb->larbid] : NULL;
int i;
if (BIT(larb->larbid) & larb->larb_gen->larb_direct_to_common_mask)
--
2.18.0
Il 08/11/21 09:24, Yong Wu ha scritto:
> We add the ostd setting for mt8195. It introduces a KE for the
> previous SoC which doesn't have ostd setting. This is the log:
>
> Unable to handle kernel NULL pointer dereference at virtual address
> 0000000000000080
> ...
> pc : mtk_smi_larb_config_port_gen2_general+0x64/0x130
> lr : mtk_smi_larb_resume+0x54/0x98
> ...
> Call trace:
> mtk_smi_larb_config_port_gen2_general+0x64/0x130
> pm_generic_runtime_resume+0x2c/0x48
> __genpd_runtime_resume+0x30/0xa8
> genpd_runtime_resume+0x94/0x2c8
> __rpm_callback+0x44/0x150
> rpm_callback+0x6c/0x78
> rpm_resume+0x310/0x558
> __pm_runtime_resume+0x3c/0x88
>
> In the code: larbostd = larb->larb_gen->ostd[larb->larbid],
> if "larb->larb_gen->ostd" is null, the "larbostd" is the offset(e.g.
> 0x80 above), it's also a valid value, then accessing "larbostd[i]" in the
> "for" loop will cause the KE above. To avoid this issue, initialize
> "larbostd" to NULL when the SoC doesn't have ostd setting.
>
> Signed-off-by: Yong Wu <[email protected]>
> ---
> change note: Reword the commit message to show why it KE. and update the
> solution via initializing "larbostd" is NULL explicitly in the non-ostd
> case.
> ---
> drivers/memory/mtk-smi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
This commit needs a Fixes tag. Please add the proper one.
Hi AngeloGioacchino,
Thanks very much for your help review.
On Thu, 2021-11-11 at 14:41 +0100, AngeloGioacchino Del Regno wrote:
> Il 08/11/21 09:24, Yong Wu ha scritto:
> > We add the ostd setting for mt8195. It introduces a KE for the
> > previous SoC which doesn't have ostd setting. This is the log:
> >
> > Unable to handle kernel NULL pointer dereference at virtual address
> > 0000000000000080
> > ...
> > pc : mtk_smi_larb_config_port_gen2_general+0x64/0x130
> > lr : mtk_smi_larb_resume+0x54/0x98
> > ...
> > Call trace:
> > mtk_smi_larb_config_port_gen2_general+0x64/0x130
> > pm_generic_runtime_resume+0x2c/0x48
> > __genpd_runtime_resume+0x30/0xa8
> > genpd_runtime_resume+0x94/0x2c8
> > __rpm_callback+0x44/0x150
> > rpm_callback+0x6c/0x78
> > rpm_resume+0x310/0x558
> > __pm_runtime_resume+0x3c/0x88
> >
> > In the code: larbostd = larb->larb_gen->ostd[larb->larbid],
> > if "larb->larb_gen->ostd" is null, the "larbostd" is the
> > offset(e.g.
> > 0x80 above), it's also a valid value, then accessing "larbostd[i]"
> > in the
> > "for" loop will cause the KE above. To avoid this issue, initialize
> > "larbostd" to NULL when the SoC doesn't have ostd setting.
> >
> > Signed-off-by: Yong Wu <[email protected]>
> > ---
> > change note: Reword the commit message to show why it KE. and
> > update the
> > solution via initializing "larbostd" is NULL explicitly in the non-
> > ostd
> > case.
> > ---
> > drivers/memory/mtk-smi.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
>
> This commit needs a Fixes tag. Please add the proper one.
This should fix this one:
fe6dd2a4017d ("memory: mtk-smi: mt8195: Add initial setting for smi-
larb")
But the commit id comes from linux-next. I'm not sure if the sha-id
will be changed again when enter mainline. so I didn't add it.
On Mon, 8 Nov 2021 16:24:29 +0800, Yong Wu wrote:
> We add the ostd setting for mt8195. It introduces a KE for the
> previous SoC which doesn't have ostd setting. This is the log:
>
> Unable to handle kernel NULL pointer dereference at virtual address
> 0000000000000080
> ...
> pc : mtk_smi_larb_config_port_gen2_general+0x64/0x130
> lr : mtk_smi_larb_resume+0x54/0x98
> ...
> Call trace:
> mtk_smi_larb_config_port_gen2_general+0x64/0x130
> pm_generic_runtime_resume+0x2c/0x48
> __genpd_runtime_resume+0x30/0xa8
> genpd_runtime_resume+0x94/0x2c8
> __rpm_callback+0x44/0x150
> rpm_callback+0x6c/0x78
> rpm_resume+0x310/0x558
> __pm_runtime_resume+0x3c/0x88
>
> [...]
Applied, thanks!
[1/1] memory: mtk-smi: Fix a null dereference for the ostd
commit: 8c5ba21c16bd7f8e23b8740dead6eaf164b8caa0
Best regards,
--
Krzysztof Kozlowski <[email protected]>